Telecommunications power systems generally employ rectifiers that generate a direct current (DC) voltage from an alternating current (AC) power source. Distribution modules include circuit breakers that connect the rectifiers to loads and that distribute current to the loads. The loads in a telecommunications power system typically include telephone switches, cellular equipment, routers and other associated equipment. In the event that AC power is lost, the telecommunications power systems generally rely on backup batteries and/or generators to provide power and to prevent costly down time. Telephone switches, cellular equipment and routers normally carry thousands of calls and/or data streams that will be interrupted if power is lost causing a significant loss of revenue.
Each of the rectifiers preferably provides a proportional share of the current that is drawn by the loads and a voltage output that is at a float voltage of the backup batteries to prevent battery discharge. Over time, the voltage output of each rectifier may drift due to differences in manufacturing tolerances, temperature variation between rectifiers, line impedance differences, and other factors. As the voltage varies, current output sharing between the rectifiers becomes less than ideal. For example, one rectifier may be operating at full rated current while another may be operating at one half of rated current due to minor operating voltage differences between the rectifiers. If this non-equal sharing continues over time, one or more of the rectifiers in the telecommunications power system may fail prematurely. Most of the time, the load is less than the rectifier's nominal power. Therefore, it is desirable to equalize the load among the rectifiers to prolong their life.
The current management system according to the invention calculates an average rectifier current output and/or an average rectifier temperature to control the voltage output of the rectifiers which, in turn, controls the current output of the rectifiers. By providing fine control of the current output of the rectifiers, current sharing and temperature stress distribution can be accomplished to prolong the life of the rectifiers and to improve voltage and current regulation of the rectifiers.
A current management system for a telecommunications power system according to the invention includes a power bus, a communications bus, and a distribution module connected to the power bus and the communications bus. A plurality of loads are connected to the distribution module. A plurality of rectifier modules are connected to the power bus, the communications bus and an AC source. Each of the rectifier modules includes a neuron that generates a rectifier current signal for the rectifier module. A master controller that is connected to the communications bus generates an average current signal from the rectifier current signals. The neurons change the voltage outputs of the rectifier modules to slightly modify the current that is output by the rectifier modules based upon the average current signal and the rectifier current signal. When the load changes suddenly, the rectifier modules are capable of supplying the load.
In other features of the invention, a temperature sensor senses a temperature of each of the rectifier modules. The master controller generates all average temperature signal from the rectifier temperature signals. The neurons generate a second rectifier control signal that slightly modifies the current that is output by the rectifier modules using the average temperature signal and the rectifier temperature signal.
Still other features will be readily apparent to skilled artisans.